Data processor, relay transmitter, and data transmission system

ABSTRACT

A data processor is configured to perform wireless communication with a relay transmitter, store a first physical address for the relay transmitter on a storage unit, receive a second physical address for the relay transmitter from the relay transmitter after the data processor being turned on, determine whether the second physical address for the relay transmitter is identical to the first physical address for the relay transmitter, and, when one or more authentication requirements is satisfied, establish wireless connection with the relay transmitter so as to achieve the data communication with an external device via the wireless communication with the relay transmitter. The authentication requirement includes the determination that the second physical address for the relay transmitter is identical to the first physical address for the relay transmitter.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority under 35 U.S.C. §119 from JapanesePatent Application No. 2009-085993 filed on Mar. 31, 2009. The entiresubject matter of the application is incorporated herein by reference.

BACKGROUND

1. Technical Field

The following description relates to one or more image transmittingtechniques.

2. Related Art

So far, a technique has been proposed in which data communication can beperformed between wireless communication devices after authentication isachieved therebetween via wireless communication. In such a technique,for example, when a user attaches a lens unit to a camera main body,wired connection is established between the camera main body and thelens unit. Thereby, the camera main body and the lens unit cancommunicate with each other.

At that time, each of the camera main body and the lens unit acquires anauthenticator, an ID, a MAC address, an IP address from the other, andstores these pieces of information onto a non-volatile memory thereof.After a series of processes as described above, the camera main body andthe lens unit can perform wireless communication with each other.

Specifically, to establish wireless connection between the camera mainbody and the lens unit, the camera main body first displays, on an LCDthereof, a list of all lens unit IDs. After the list is displayed, whenthe user operates an operation key to select one of lens unitscorresponding to the lens unit IDs displayed, the camera main body readsout an authenticator of the selected lens unit from the non-volatilememory.

Then, the camera main body issues, to the selected lens unit, aconnection request that includes the read authenticator, the MAC addressof the camera main body, and the lens unit ID. On the other hand, thelens unit receives the connection request from the camera main body anddetermines whether the lens unit ID thereof is identical to the lensunit ID included in the received connection request.

As a result, when determining that the lens unit ID thereof is identicalto the lens unit ID included in the received connection request, thelens unit reads, out of the non-volatile memory thereof, a main body IDand an authenticator that correspond to the received MAC address of thecamera main body. Then, the lens unit determines whether the read mainbody ID and authenticator are identical to those included in thereceived connection request.

When determining that the read main body ID and authenticator areidentical to those included in the received connection request, the lensunit transmits a response “OK” to the camera main body. After that, thelens unit can be operated from the side of the camera main body viawireless communication using the IP addresses previously exchangedtherebetween.

SUMMARY

In the meantime, in a conventional multi-function peripheral (MFP) or aconventional facsimile machine, a unit that performs communication withother facsimile machines and a unit that inputs or outputs images (e.g.,reads, prints, or displays images) are incorporated in a single housing.In such an integrated device, when accepting initial default settings, auser can generally perform facsimile communication merely by turning onthe device.

Meanwhile, according to an image transmission system in which a unitthat communicates with other facsimile machines and a unit that inputsor outputs images are incorporated in respective different housings andperform data transmission therebetween via wireless communication,unlike the aforementioned integrated device, a user cannot performfacsimile communication until the two units are wirelessly connectedwith each other even after the two units are turned on.

However, for instance, in the case of the aforementioned technique forwireless connection between the camera main body and the lens unit, thewireless connection is not established therebetween until the userattaches the lens unit to the camera main body.

In other words, the technique does not make it possible to establish thewireless connection between the camera main body and the lens unitmerely by turning on the camera main body and the lens unit just afterpurchasing the camera main body and the lens unit. Therefore,unfortunately, even though the technique is applied to theaforementioned image transmission system configured with the separateunits, it is difficult to attain the same operability anduser-friendliness as the aforementioned integrated device.

Aspects of the present invention are advantageous to provide one or moreimproved techniques that make it possible to establish wirelessconnection between devices merely by turning on the devices.

According to aspects of the present invention, a data processor isprovided that is configured to perform data communication with anexternal device via wireless communication with a relay transmitter. Thedata processor includes a communication unit configured to performwireless communication with the relay transmitter, a storage unitconfigured to store a first physical address for the relay transmitter,an authentication starter configured to, in response to the dataprocessor being turned on, transmit, to the relay transmitter, aninstruction to start authentication between the data processor and therelay transmitter along with a physical address for the data processor,an address receiver configured to receive a second physical address forthe relay transmitter from the relay transmitter as a response to theinstruction, a determining unit configured to make a determination as towhether the second physical address for the relay transmitter isidentical to the first physical address for the relay transmitter, and aconnecting unit configured to, when one or more authenticationrequirements are satisfied, establish wireless connection between thecommunication unit and the relay transmitter so as to achieve the datacommunication between the data processor and the external device via therelay transmitter, the authentication requirements including thedetermination by the determining unit that the second physical addressfor the relay transmitter is identical to the first physical address forthe relay transmitter.

According to aspects of the present invention, further provided is arelay transmitter, which includes a first communication unit configuredto perform wireless communication with an data processor, a secondcommunication unit configured to perform data communication with anexternal device, a storage unit configured to store a first physicaladdress for the data processor, an address receiver configured to, inresponse to the relay transmitter being turned on, receive, from thedata processor, a second physical address for the data processor alongwith an instruction to start authentication between the data processorand the relay transmitter, a determining unit configured to, in responseto the instruction from the data processor, make a determination as towhether the second physical address for the data processor is identicalto the first physical address for the data processor, and a connectingunit configured to, when one or more authentication requirements aresatisfied, transmit a physical address for the relay transmitter to thedata processor and establish wireless connection between the firstcommunication unit and the data processor so as to achieve datacommunication between the data processor and the external device via therelay transmitter, the authentication requirements including thedetermination by the determining unit that the second physical addressfor the data processor is identical to the first physical address forthe data processor.

According to aspects of the present invention, further provided is adata transmission system, which includes a relay transmitter configuredto perform data communication with an external device, and an dataprocessor configured to perform data communication with the externaldevice via wireless communication with the relay transmitter. The dataprocessor includes a communication unit configured to perform wirelesscommunication with the relay transmitter, a storage unit configured tostore a first physical address for the relay transmitter, anauthentication starter configured to, in response to the data processorbeing turned on, transmit, to the relay transmitter, an instruction tostart authentication between the data processor and the relaytransmitter along with a physical address for the data processor, anaddress receiver configured to receive a second physical address for therelay transmitter from the relay transmitter as a response to theinstruction, a determining unit configured to make a determination as towhether the second physical address for the relay transmitter isidentical to the first physical address for the relay transmitter, and aconnecting unit configured to, when one or more authenticationrequirements are satisfied, establish wireless connection between thecommunication unit and the relay transmitter so as to achieve the datacommunication between the data processor and the external device via therelay transmitter, the authentication requirements including thedetermination by the determining unit that the second physical addressfor the relay transmitter is identical to the first physical address forthe relay transmitter. The relay transmitter includes a firstrelay-transmitter-side communication unit configured to perform wirelesscommunication with the data processor, a second relay-transmitter-sidecommunication unit configured to perform data communication with theexternal device, a relay-transmitter-side storage unit configured tostore a first physical address for the data processor, arelay-transmitter-side address receiver configured to, in response tothe relay transmitter being turned on, receive, from the data processor,a second physical address for the data processor along with theinstruction to start authentication between the data processor and therelay transmitter, a relay-transmitter-side determining unit configuredto, in response to the instruction from the data processor, make adetermination as to whether the second physical address for the dataprocessor is identical to the first physical address for the dataprocessor, and a relay-transmitter-side connecting unit configured to,when the authentication requirements are satisfied, transmit a physicaladdress for the relay transmitter to the data processor and establishwireless connection between the first communication unit and the dataprocessor so as to achieve the data communication between the dataprocessor and the external device via the relay transmitter, theauthentication requirements including the determination by therelay-transmitter-side determining unit that the second physical addressfor the data processor is identical to the first physical address forthe data processor.

In some aspects of the present invention, the physical address for thedata processor may be employed for uniquely identifying a wirelesscommunication interface (hardware for wireless communication) of thedata processor on a wireless network containing thereon the dataprocessor and the relay transmitter. In the same manner, the physicaladdress for the relay transmitter may be employed for uniquelyidentifying a wireless communication interface (hardware for wirelesscommunication) of the relay transmitter on the wireless network.

As a typical example of such a physical address, a media access control(MAC) address is cited. Nevertheless, a different physical address fromthe MAC address may be used depending on an applied communicationstandard (e.g., Bluetooth (trademark registered)).

In general, such a physical address is previously assigned as a uniqueaddress to an individual wireless communication interface, and stored ona non-volatile memory of the wireless communication interface. In someaspects of the present invention, however, each of the data processorand the relay transmitter may have a non-volatile storage unit separatefrom the non-volatile memory of the wireless communication interfacethereof. On the non-volatile storage unit, stored is the physicaladdress assigned to the wireless communication interface of the otherdevice (i.e., a communication target device).

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

FIGS. 1A and 1B exemplify respective overall network configurations eachof which includes an image transmission system and an external device inan embodiment according to one or more aspects of the present invention.

FIG. 2A is a block diagram schematically showing a configuration of animage processor in the embodiment according to one or more aspects ofthe present invention.

FIG. 2B is a block diagram schematically showing a configuration of arelay transmitter in the embodiment according to one or more aspects ofthe present invention.

FIG. 3 is a flowchart showing a procedure of a process to be executed bythe image processor in the embodiment according to one or more aspectsof the present invention.

FIG. 4 is a flowchart showing a procedure of a process to be executed bythe relay transmitter in the embodiment according to one or more aspectsof the present invention.

FIG. 5 is a sequence diagram showing in sequence respective states ofthe image processor and the relay transmitter until wireless connectionis established therebetween in the embodiment according to one or moreaspects of the present invention.

DETAILED DESCRIPTION

It is noted that various connections are set forth between elements inthe following description. It is noted that these connections in generaland, unless specified otherwise, may be direct or indirect and that thisspecification is not intended to be limiting in this respect. Aspects ofthe invention may be implemented in computer software as programsstorable on computer-readable media including but not limited to RAMs,ROMs, flash memories, EEPROMs, CD-media, DVD-media, temporary storage,hard disk drives, floppy drives, permanent storage, and the like.

Hereinafter, an embodiments according to aspects of the presentinvention will be described with reference to the accompany drawings.

[Overall Configuration of Image Transmission System]

As illustrated in FIGS. 1A and 1B, an image transmission system in theembodiment, which is configured to transmit and receive images viafacsimile communication, includes an image processor 1 and a relaytransmitter 2. As shown in FIG. 1A, the image processor 1 and the relaytransmitter 2 can perform direct wireless communication with each other.Further, as shown in FIG. 1B, when the image transmission system has anaccess point 3, the image processor 1 and the relay transmitter 2 canperform indirect wireless communication via the access point 3. Inaddition, via the relay transmitter 2 which is connected with a publicswitched telephone networks (PSTN) 4, the image processor 1 cancommunicate with an external facsimile machine 5 outside the imagetransmission system. Furthermore, when performing communication via theaccess point 3, as shown in FIG. 1B, the image processor 1 cancommunicate with a wireless communication device 6 other than the relaytransmitter 2.

As illustrated in FIG. 2A, the image processor 1 includes a CPU 10, adisplay unit 11, a button input unit 12, a panel 13, a ROM 14A, a RAM14B, an EEPROM 14C, a USB interface 15, a recording unit 16, a readingunit 17, and a wireless communication unit 18. Among the above elements,the display unit 11, the button input unit 12, the panel 13, the ROM14A, the RAM 14B, the EEPROM 14C, the USB interface 15, the recordingunit 16, the reading unit 17 are substantially the same as those of ageneral MFP.

The CPU 10 is configured to control each element of the image processor1 in accordance with a control program stored on the ROM 14A. Thedisplay unit 11 is provided with a liquid crystal display (LCD) andconfigured to display various kinds of information. For example, thedisplay unit 11 is utilized to display a received facsimile imagewithout printing the image. The button input unit 12 and the panel 13are utilized when a user performs an input operation therethrough to usevarious functions of the image processor 1.

The ROM 14A stores information that is not required to be rewritten,such as a program for controlling the image processor 1. The RAM 14Bstores data that causes no problem even though disappearing in responseto the image processor 1 being turned off. The EEPROM 14C stores varioussetting data that is required to remain even when the image processor 1is turned off. The USB interface 15 is an input/output (I/O) interfaceto be utilized when a device complying with the USB standard isconnected with the image processor 1.

The recording unit 16 is provided with a printing mechanism using aninkjet method or an electrophotographic method and configured to form animage on a sheet in a printer function, a copy function, or a facsimilereceiving function. The reading unit 17 is provided with an image sensorand an automatic document feeder (ADF) and configured to optically readan image from a document sheet in a scanner function, the copy function,or a facsimile transmitting function.

The image processor 1 has the wireless communication unit 18, forperforming wireless communication with the relay transmitter 2, which isnot included in a general MFP. Specifically, a general MFP has beenknown that includes a wireless communication unit connectable with awireless network. However, the wireless communication unit 18 of theimage processor 1 is not only connectable with a wireless network butadapted to perform wireless communication with the relay transmitter 2.In this respect, the image processor 1 is different from the general MFPwhich does not support a device corresponding to the relay transmitter2.

More specifically, the wireless communication unit 18 includes a normalcommunication section 18A, an encryption/decryption communicationsection 18B, a particular-data determining section 18C, a wireless LANcommunication section 18D, and a wireless LAN antenna section 18E.

The normal communication section 18A generates transmission data to betransmitted in a normal procedure or analyzes received data that hasbeen transmitted in a normal procedure, before the image processor 1 isready to perform encrypted communication with the relay transmitter 2,or when the image processor 1 attempts to communicate with a device(e.g., the wireless communication device 6) other than the relaytransmitter 2.

The encryption/decryption communication section 18B encrypts data in anencryption method specific to the image processor 1 and the relaytransmitter 2, or decrypts or analyzes received data that has beentransmitted in a state encrypted in an encryption method specific to theimage processor 1 and the relay transmitter 2, when the image processor1 attempts to communicate with the relay transmitter 2 after being readyto perform encrypted communication with the relay transmitter 2.

The particular-data determining section 18C transmits data to thewireless LAN communication section 18D with a flag set in the data,which flag represents through which section, between the normalcommunication section 18A and the encryption/decryption communicationsection 18B, data is transmitted. Further, when receiving data, theparticular-data determining section 18C sorts the received data into oneof the normal communication section 18A and the encryption/decryptioncommunication section 18B, based on a flag in the received data.

In the embodiment, the wireless LAN communication section 18D complieswith a wireless LAN standard (e.g., IEEE802.11 standards such asIEEE802.11a, IEEE802.11b, and IEEE802.11g), and is configured to switcha communication mode of the image processor 1 between an infrastructuremode and an ad hoc mode.

When switching the communication mode to the ad hoc mode, as illustratedin FIG. 1A, the image processor 1 can communicate directly with therelay transmitter 2 by establishing wireless connection with the relaytransmitter 2. Further, when switching the communication mode to theinfrastructure mode, as illustrated in FIG. 1B, the image processor 1can communicate with the relay transmitter 2 or devices other than therelay transmitter 2 (e.g., the wireless communication device 6) via theaccess point 3 by establishing wireless connection with the access point3.

In addition, the wireless LAN communication section 18D has a physicaladdress (MAC address) assigned thereto that is used for wirelesscommunication. The physical address is stored on a non-volatile memory(not shown) incorporated in the wireless LAN communication section 18D.The physical address corresponds to the image processor 1.

On the other hand, as illustrated in FIG. 2B, the relay transmitter 2includes a CPU 20, a display unit 21, a button input unit 22, a panel23, a ROM 24A, a RAM 24B, an EEPROM 24C, a USB interface 25, a wirelesscommunication unit 28, and an external-line communication unit 29.

The CPU 20 controls each element included in the relay transmitter 2 inaccordance with a control program stored on the ROM 24A. The displayunit 21 is provided with a liquid crystal display and configured todisplay various kinds of information. For example, the display unit 21is utilized for displaying incoming and outgoing call registers.Further, the button input unit 22 and the panel are utilized for theuser to perforin input operations therethrough to use functions of therelay transmitter 2.

The ROM 24A stores information that is not required to be rewritten,such as a program for controlling the relay transmitter 2. The RAM 24Bstores data that would cause no problem even though disappearing whenthe relay transmitter 2 is turned off. The EEPROM 24C stores variouskinds of setting data that is desired to remain even though the relaytransmitter 2 is turned off. In the embodiment, the aforementionedphysical address for the image processor 1 is stored on the EEPROM 24Cas well. It is noted that, for example, the physical address for theimage processor 1 may be stored on the EEPROM 24C as a factory defaultsetting. Alternatively, the physical address for the image processor 1may be stored before supplied to the user after set in some way (e.g.,by a service person). The USB interface 25 is an input/output (I/O)interface to be utilized when a device complying with the USB standardis connected with the relay transmitter 2.

The wireless communication unit 28 is provided for wirelesscommunication with the image processor 1. In the same manner as theimage processor 1, the wireless communication unit 28 includes a normalcommunication section 28A, an encryption/decryption communicationsection 28B, an particular-data determining section 28C, a wireless LANcommunication section 28D, and a wireless LAN antenna section 28E.

The normal communication section 28A generates transmission data to betransmitted in a normal procedure or analyzes received data that hasbeen transmitted in a normal procedure, when the relay transmitter 2attempts to communicate with the image processor 1 before being ready toperform encrypted communication with the image processor 1.

The encryption/decryption communication section 28B encrypts data in anencryption method specific to the image processor 1 and the relaytransmitter 2, or decrypts or analyzes received data that has beentransmitted in a state encrypted in an encryption method specific to theimage processor 1 and the relay transmitter 2, when the relaytransmitter 2 attempts to communicate with the image processor 1 afterbeing ready to perform encrypted communication with the image processor1.

The particular-data determining section 28C transmits data to thewireless LAN communication section 28D with a flag set in the data,which flag represents through which, of the normal communication section28A and the encryption/decryption communication section 28B, data istransmitted. Further, when receiving data, the particular-datadetermining section 28C sorts the received data into one of the normalcommunication section 28A and the encryption/decryption communicationsection 28B, based on a flag in the received data.

The wireless LAN communication section 28D complies with the samewireless LAN standard as the standard with which the wireless LANcommunication section 18D of the image processor 1 complies. Thewireless LAN communication section 28D is configured to switch acommunication mode of the relay transmitter 2 between the infrastructuremode and an ad hoc mode.

When switching the communication mode to the ad hoc mode, as illustratedin FIG. 1A, the relay transmitter 2 can communicate directly with theimage processor 1 by establishing wireless connection with the imageprocessor 1. Further, when switching the communication mode to theinfrastructure mode, as illustrated in FIG. 1B, the relay transmitter 2can communicate with the image processor 1 via the access point 3 byestablishing wireless connection with the access point 3.

In addition, the wireless LAN communication section 28D has a physicaladdress (MAC address) assigned thereto that is to be used for wirelesscommunication. The physical address is stored on a non-volatile memory(not shown) incorporated in the wireless LAN communication section 28D.The physical address corresponds to the relay transmitter 2. In theembodiment, for example, the physical address for the relay transmitter2 may be stored, as a factory default setting, on the EEPROM 14C aswell.

The external-line communication unit 29 is an element which is notprovided to a general MFP. The external-line communication unit 29includes a modem 29A and a telephone line connection section 29B. Themodem 29A is configured to convert one of digital data and a soundsignal into the other. The telephone line connection section 29Bconfigured to perform a communication operation (e.g., operations ofmaking an outgoing call and receiving an incoming call) in utilizing avoice communication function or a facsimile function.

Owing to collaboration between the image processor 1 and the relaytransmitter 2 configured as above, the image transmission system as awhole attains the same functions as a known MFP and a known facsimilemachine. In other words, in the image transmission system, the imageprocessor 1 serves as a portion that mainly inputs and outputs images(e.g., reads, prints, and displays images) while the relay transmitter 2serves as a portion that mainly communicates with a destination device(e.g., the facsimile machine 5).

More specifically, when an image is transmitted using the imageprocessor 1 and the relay transmitter 2, the image is transmitted by thewireless communication unit 18 of the image processor 1 to the wirelesscommunication unit 28 of the relay transmitter 2 via wirelesscommunication using a wireless LAN method. Then, the transmitted imageis sent by the external-line communication unit 29 of the relaytransmitter 2 to a destination device (e.g., the facsimile machine 5)via the PSTN 4.

Meanwhile, when an image is received using the image processor 1 and therelay transmitter 2, the image, transmitted by a transmitting sourcedevice (e.g., the facsimile device 5) via the PSTN 4, is received by theexternal-line communication unit 29 of the relay transmitter 2. Then,the received image is transmitted by the wireless communication unit 28of the relay transmitter 2 to the wireless communication unit 18 of theimage processor 1 via wireless communication using the wireless LANmethod. Thereafter, the image is displayed on the display unit 11 of theimage processor 1 or printed by the recording unit 16 of the imageprocessor 1.

[Processes Executed by Image Processor and Relay Transmitter]

Subsequently, explanations will be provided about processes to beexecuted by the image processor 1 and the relay transmitter 2 in orderto attain the aforementioned image transmission system, with referenceto FIGS. 3 and 4. It is noted that a flowchart illustrated in FIG. 3shows major ones of steps to be executed by the image processor 1. It isnoted that a flowchart illustrated in FIG. 4 shows major ones of stepsto be executed by the relay transmitter 2.

When the image processor 1 is powered on, the CPU 10 of the imageprocessor 1 begins to execute a process shown in FIG. 3. When startingthe process, the CPU 10 creates a service set identifier (SSID) and awired equivalent privacy (WEP) from the physical addresses (MACaddresses), and saves settings therefor (S105). Then, the CPU 10 setsthe communication mode of the wireless communication unit 18 to the adhoc mode (S110).

The SSID created in D105 is an identifier corresponding to a networkname of a wireless network established between the image processor 1 andthe relay transmitter 2. Further, the WEP created in S105 is one ofencryption standards for a wireless LAN that employs a common keyencryption method.

In the embodiment, both the SSID and the WEP are created based on thephysical address for the image processor 1 and the physical address forthe relay transmitter 2. The physical address for the image processor 1is read out of the non-volatile memory inside the wireless LANcommunication section 18D. Additionally, the physical address for therelay transmitter 2 is read out of the EEPROM 14C, which has thephysical address for the relay transmitter 2 stored thereon, e.g., as afactory default setting. It is noted that the physical address for therelay transmitter 2 may be stored on the EEPROM 14C before supplied tothe user after set in some way (e.g., by a service person).

In the embodiment, each of the two physical addresses has 12 digits in ahexadecimal form. It is assumed that the physical address for the imageprocessor 1 is expressed with “ZYXWVUTSRQPO” (it is noted that each ofthe twelve symbols “Z” to “O” for the twelve digits is any of values “0”to “f” for representing each digit of a hexadecimal number) and thephysical address for the relay transmitter 2 is expressed with“ABCDEFGHIJKL” (it is noted that the twelve symbols “A” to “L” for thetwelve digits are any of the values “0” to “f” for representing eachdigit of a hexadecimal number). Under such an assumption, in S105, theCPU 10 extracts the last six digits from each of the two physicaladdresses and determines, as the SSID, a hexadecimal number of twelvedigits created by rearranging the respective twelve values for theextracted twelve digits in an order “GTHSIRJQKPLO.” Further, the CPU 10determines, as the WEP, a hexadecimal number of thirteen digits createdby rearranging the respective twelve values for the extracted twelvedigits in an order “LOKPJQIRHSGTG.”

It is noted that the above “GTHSIRJQKPLO” and “LOKPJQIRHSGTG” are justexamples of the rearrangement orders of the respective values for theextracted twelve digits in creating the SSID and the WEP. Thearrangement orders or the digits to be extracted may be changed. In thisrespect, however, the image processor 1 and the relay transmitter 2 arerequired to apply an identical rearrangement order for the SSID and anidentical rearrangement order for the WEP under a common rule betweenthe image processor 1 and the relay transmitter 2.

Next, the CPU 10 creates an advanced encryption standard (AES)encryption key from the physical addresses, and saves the AES encryptionkey (S115). The AES is one of common key encryption methods. In S115,the CPU 10 extracts twelve digits from each of the two physicaladdresses, and determines, as the AES encryption key, a hexadecimalnumber of 24 digits created by rearranging the respective 24 values forthe extracted 24 digits in an order “AZBYCXDWEVFUGTHSIRJQKPLO.”

After creating the AES encryption key determined as above (S115), theCPU 10 configures an initial setting concerning the wireless network(S120). Then, to start wireless communication, the CPU 10 begins totransmit the SSID (S125). After that, the CPU 10 establishes an ad hocnetwork with the relay transmitter 2 (S130). Thereafter, the CPU 10automatically assigns thereto (to the image processor 1) a logic address(IP address) using automatic private IP addressing (APIPA) (S135). TheAPIPA is a function that causes a device, having the function, toretrieve an unused IP address on a network of the device and to assignthe unused IP address to the device when there is not on the network anexternal device (e.g., a DHCP server) having a function to assign an IPaddress to the device.

After the logic address is completely assigned in S135, the CPU 10retrieves management information within the network based on a simplenetwork management protocol (SNMP) (S140). When a response to theretrieving operation in S140 is transmitted by the relay transmitter 2,the CPU 10 receives the response and acquires a “physical address forthe relay transmitter 2” included in the response. Then, the CPU 10determines whether the acquired “physical address for the relaytransmitter 2” is identical to the “physical address for the relaytransmitter 2” stored on the EEPROM 14C, by comparing both the physicaladdresses with each other (S145).

When determining that both the physical addresses are not identical toeach other (S145: No), the CPU 10 displays on the display unit 11information on the unsuccessful connection with the relay transmitter 2(S150). After that, the CPU 10 terminates the present process shown inFIG. 3. Meanwhile, when determining that both the physical addresses areidentical to each other (S145: Yes), the CPU 10 cannot definitelydetermine yet at this stage whether the response has been transmitted bythe relay transmitter 2 or another wireless communication device thatmasquerades as the relay transmitter 2.

Therefore, the CPU 10 starts authentication to establish wirelessconnection with the relay transmitter 2 (S155). The CPU 10 controls theencryption/decryption communication section 18B to encrypt aninstruction to start the authentication and the physical address for theimage processor 1 with the AES encryption key (S160). Then, the CPU 10controls the particular-data determining section 18C to add the flag tothe encrypted data and transmit the encrypted data with the flag settherein to the relay transmitter 2 as particular data (S165).

When a response to the particular data (the instruction to start theauthentication) transmitted in S165 is returned by the relay transmitter2 (S170: Yes), the CPU 10 determines whether the response is particulardata (S175). It is noted that when the response is proper, the responseshould be particular data encrypted with the AES encryption key.

When determining that the response is particular data (S175: Yes), theCPU 10 controls the encryption/decryption communication section 18B todecrypt the encrypted data (i.e., the response from the relaytransmitter 2) with AES encryption key (S180). Then, the CPU 10determines whether the decrypted data is a response to (the instructionto start) the authentication from the relay transmitter 2 (S185).

When determining that the decrypted data is a response to theauthentication from the relay transmitter 2 (S185: Yes), the CPU 10determines whether a “physical address for the relay transmitter 2”included in the response is identical to the “physical address for therelay transmitter 2” stored on the EEPROM 14C, by comparing both thephysical addresses (S190).

When determining that both the physical addresses are identical to eachother (S190: Yes), the CPU 10 stores the logic address of the relaytransmitter 2 onto the EEPROM 14C (S195), and displays on the displayunit 11 information on the successful connection with the relaytransmitter 2 (S200). After that, the CPU 10 terminates the presentprocess shown in FIG. 3.

When no response to the particular data transmitted in S165 is returnedby the relay transmitter 2 (S170: No), or a response transmitted by therelay transmitter 2 is not particular data (S175: No), or both thephysical addresses are not identical to each other (S190: No), the CPU10 goes to S150, in which the CPU 10 displays on the display unit 11information that the image processor 1 is not successfully connectedwith the relay transmitter 2 (S150). Thereafter, the CPU 10 terminatesthe present process shown in FIG. 3.

In parallel with the aforementioned process being executed by the imageprocessor 1, the relay transmitter 2 performs a process shown in FIG. 4.In other words, when the relay transmitter 2 is powered on, the CPU 20of the relay transmitter 2 starts the process shown in FIG. 4. Among thesteps shown in FIG. 4, S305 to S335 are substantially the same as S105to S135 executed by the image processor 1, respectively.

Specifically, the CPU 20 first creates an SSID and an WEP from thephysical addresses (MAC addresses), and saves settings therefor (S305).Then, the CPU 20 sets the communication mode of the wirelesscommunication unit 28 to the ad hoc mode (S310). It is noted that theSSID and the WEP are the same as those created in S105.

Subsequently, the CPU 20 creates an AES encryption key from the physicaladdresses, and saves the AES encryption key (S315). The AES encryptionkey created in S315 is the same as that created in S115.

After creating the AES encryption key (S315), the CPU 20 configures aninitial setting concerning the wireless network (S320). Then, to startwireless communication, the CPU 20 begins to transmit the SSID (S325).After that, the CPU 20 establishes an ad hoc network with the imageprocessor 1 (S330). Thereafter, the CPU 20 automatically assigns theretoa logic address (IP address) using the APIPA (S335).

After the logic address is completely assigned in S335, the CPU 20determines whether the CPU 20 has received a request for managementinformation (S340). Here, when the image processor 1 performs theaforementioned step S140, the CPU 20 determines in S340 that the CPU 20has received a request for management information (S340: Yes). In thatcase, the CPU 20 transmits, to the image processor 1, a response thatincludes information regarding the logic address and the physicaladdress for the relay transmitter 2 (S345). The response transmitted inS345 is the aforementioned response that includes the information (i.e.,the physical address for the relay transmitter 2) to be compared withthe physical address for the relay transmitter 2 stored on the EEPROM14C in S145. After execution of S345, the CPU 20 goes to S350.Meanwhile, when determining in S340 that the CPU 20 has not received arequest for management information (S340: No), the CPU 20 goes to S350without executing S345.

In S350, the CPU 20 determines whether the CPU 20 has receivedparticular data from the image processor 1 (S350). It is noted that theparticular data, which the CPU 20 determines in S350 whether the CPU 20has received, is transmitted in the aforementioned step S165.

When determining that the CPU 20 has received particular data from theimage processor 1 (S350: Yes), the CPU 20 controls theencryption/decryption communication section 28B to decrypt theparticular data with the AES encryption key (S355). Thereafter, the CPU20 determines whether the particular data includes the instruction tostart the authentication (S360).

When determining that the particular data includes the instruction tostart the authentication (S360: Yes), the CPU 20 further decrypts thereceived particular data to acquire a physical address (S365). Then, theCPU 20 compares the acquired “physical address for the image processor1” with the “physical address for the image processor 1” stored on theEEPROM 24C, and determines whether both the physical addresses areidentical to each other (S370).

When determining that both the physical addresses are identical to eachother (S370: Yes), the CPU 20 controls the encryption/decryptioncommunication section 28B to encrypt a response to (the instruction tostart) the authentication and the physical address of the relaytransmitter 2 with the AES encryption key (S375). Then, the CPU 20controls the particular-data determining section 28C to add the flag tothe encrypted data and transmit the encrypted data with the flag settherein to the image processor 1 as particular data (S380).

Subsequently, the CPU 20 stores the logic address of the image processor1 onto the EEPROM 24C (S385). Thereafter, the CPU 20 terminates theprocess shown in FIG. 4. Meanwhile, when the CPU 20 has not receivedparticular data from the image processor 1 (S350: No), or the receivedparticular data does not include the instruction to start theauthentication (S360: No), or both the physical addresses are notidentical to each other (S370: No), the CPU 20 terminates the processshown in FIG. 4.

As described above, when the image processor 1 performs the processshown in FIG. 3 and the relay transmitter 2 performs the process shownin FIG. 4, communication is established and performed between the imageprocessor 1 and the relay transmitter 2, e.g., in accordance with aprocedure as illustrated in a sequence diagram of FIG. 5.

Namely, the image processor 1 performs the steps S105 to S135 inresponse to the image processor 1 being powered on, so as to create theSSID, the WEP, and the AES encryption key from the physical addressesfor both the image processor 1 and the relay transmitter 2 and establishcommunication environments for wireless communication in the ad hocmode. In the same manner, the relay transmitter 2 performs the stepsS305 to S335 in response to the relay transmitter 2 being powered on, soas to create the SSID, the WEP, and the AES encryption key from thephysical addresses for both the image processor 1 and the relaytransmitter 2 and establish communication environments for wirelesscommunication in the ad hoc mode.

Then, when the ad hoc communication is established, the image processor1 retrieves management information within the network based on the SNMPin S140. In response to the retrieving operation, the relay transmitter2 transmits to the image processor 1 the physical address and the logicaddress for the relay transmitter 2 in S345. It is noted that by thistime, an encrypting operation with the AES encryption key has not yetbeen performed.

After the aforementioned communication, the image processor 1 recognizesa device which may be the relay transmitter 2. Therefore, subsequentlyin S155 to S165, the image processor 1 transmits, to the relaytransmitter 2, the instruction to start the authentication along withthe physical address of the image processor 1 in an encrypted manner. Inresponse to receipt of the instruction, the relay transmitter 2transmits the response to the authentication along with the physicaladdress of the relay transmitter 2 in an encrypted manner in S375 toS380. Thereby, both the image processor 1 and the relay transmitter 2recognize each other as a device with which communication can beperformed using a common encryption key, and thus determine each otherto be a proper device with which communication is to be established.Then, both the image processor 1 and the relay transmitter 2 registertheir logic addresses onto the EEPROM 14C and the EEPROM 24C,respectively. After that, encrypted communication can be achievedbetween the image processor 1 and the relay transmitter 2.

[Effects]

As described above, according to the image transmission system includingthe image processor 1 and the relay transmitter 2, it is possible tocertainly establish wireless connection between the image processor 1and the relay transmitter 2 by turning on the image processor 1 and therelay transmitter 2. Thereby, the image transmission system is set to beable to perform facsimile communication. Further, even though one ormore other wireless communication devices are present near the imageprocessor 1 and the relay transmitter 2 when the image processor 1 andthe relay transmitter 2 are powered on, the image processor 1 and therelay transmitter 2 authenticate each other with the physical address ofeach other. Hence, each of the image processor 1 and the relaytransmitter 2 does not establish wireless connection with a device otherthan the image processor 1 and the relay transmitter 2. Thus, it ispossible to prevent any of the image processor 1 and the relaytransmitter 2 from establishing wireless connection with an undesireddevice.

Further, according to the aforementioned image transmission system, eachof the image processor 1 and the relay transmitter 2 stores the physicaladdresses of both the image processor 1 and the relay transmitter 2, andcreates the same network name based on the two physical addresses. Then,by using the same network name created, each of the image processor 1and the relay transmitter 2 serves as a node of the same wirelessnetwork and performs wireless communication. Accordingly, even thoughanother wireless network is present near the image processor 1 and therelay transmitter 2, another wireless communication device can hardlyuse the same network name. In addition, even though a different device(an image processor or a relay transmitter) of the same type as theimage processor 1 or the relay transmitter 2 is present near the imageprocessor 1 and the relay transmitter 2 when the image processor 1 andthe relay transmitter 2 establish wireless connection therebetween, itis possible to establish a wireless network of a network name that isdifferent from a network name of a network of the different device.Thus, it is possible to enhance the effect to prevent any of the imageprocessor 1 and the relay transmitter 2 from establishing wirelessconnection with an undesired device.

Further, according to the aforementioned image transmission system, eachof the image processor 1 and the relay transmitter 2 stores the physicaladdresses of both the image processor 1 and the relay transmitter 2, andcreates the same encryption key based on the two physical addresses.Then, by using the same encryption key created, each of the imageprocessor 1 and the relay transmitter 2 performs the same encryptedcommunication in the same encryption method. Accordingly, when the imageprocessor 1 and the relay transmitter 2 perform wireless communicationtherebetween, a third party, who does not know the physical addresses ofthe image processor 1 and the relay transmitter 2, can hardly decryptencrypted data. Thus, it is possible to transmit and receiveconfidential data between the image processor 1 and the relaytransmitter 2.

In addition, according to the aforementioned image transmission system,when authentication is established between the image processor 1 and therelay transmitter 2, an encryption key usable only therebetween is usedfor encrypted communication therebetween. In the meantime, the imageprocessor 1 is configured to communicate with the wireless communicationdevice 6 other than the relay transmitter 2. However; in this situation,the image processor 1 performs wireless communication with the wirelesscommunication device 6 without using the encryption key created for thecommunication with the relay transmitter 2. Accordingly, even thoughcommunication is performed between the image processor 1 and the relaytransmitter 2, the wireless communication device 6 cannot decrypt dataexchanged between the image processor 1 and the relay transmitter 2.Thus, it is possible to exchange highly confidential data between theimage processor 1 and the relay transmitter 2. Additionally, the imageprocessor 1 can establish wireless connection with the wirelesscommunication device 6 which cannot recognize the encryption key createdin the image processor 1 and the relay transmitter 2. Therefore, anotherdevice such as the wireless communication device 6 can easily utilizethe image processor 1.

Hereinabove, the embodiment according to aspects of the presentinvention has been described. The present invention can be practiced byemploying conventional materials, methodology and equipment.Accordingly, the details of such materials, equipment and methodologyare not set forth herein in detail. In the previous descriptions,numerous specific details are set forth, such as specific materials,structures, chemicals, processes, etc., in order to provide a thoroughunderstanding of the present invention. However, it should be recognizedthat the present invention can be practiced without reapportioning tothe details specifically set forth. In other instances, well knownprocessing structures have not been described in detail, in order not tounnecessarily obscure the present invention.

Only an exemplary embodiment of the present invention and but a fewexamples of their versatility are shown and described in the presentdisclosure. It is to be understood that the present invention is capableof use in various other combinations and environments and is capable ofchanges or modifications within the scope of the inventive concept asexpressed herein. For example, the following modifications are possible.

In the aforementioned embodiment, the image transmission system isexemplified which is configured to perform facsimile communication(i.e., to transmit and receive facsimile data). However, aspects of thepresent invention may be applied to an image transmission systemconfigured just for transmitting facsimile data or an image transmissionsystem configured just for receiving facsimile data.

In the aforementioned embodiment, the image processor 1 and the relaytransmitter 2 authenticate each other as a target device with whichwireless connection is to be established, using the physical address ofeach other. Further, the image processor 1 and the relay transmitter 2create the same network name and the same encryption key. Nevertheless,the network name and the encryption key may not necessarily beassociated with the physical addresses for the image processor 1 and therelay transmitter 2. In this respect, however, when the network name andthe encryption key are created in association with the physicaladdresses for the image processor 1 and the relay transmitter 2 asexemplified in the aforementioned embodiment, the image transmissionsystem can handle more highly confidential information that would hardlybe decrypted by any other wireless communication device.

What is claimed is:
 1. A data processor configured to perform datacommunication with an external device via wireless communication with arelay transmitter, the data processor comprising: a communication unitconfigured to perform wireless communication with the relay transmitter;a storage unit configured to store a first physical address for therelay transmitter; an authentication starter configured to, in responseto the data processor being turned on, wirelessly transmit, to the relaytransmitter, an instruction to start authentication between the dataprocessor and the relay transmitter along with a physical address forthe data processor; an address receiver configured to receive a secondphysical address for the relay transmitter wirelessly transmitted fromthe relay transmitter as a response to the instruction; a determiningunit configured to make a determination as to whether the secondphysical address for the relay transmitter which is received from therelay transmitter wirelessly is identical to the first physical addressfor the relay transmitter which had been stored in the storage unitbefore the data processor is turned on; and a connecting unit configuredto, when one or more authentication requirements are satisfied,establish wireless connection between the communication unit and therelay transmitter so as to achieve the data communication between thedata processor and the external device via the relay transmitter, theauthentication requirements including the determination by thedetermining unit that the second physical address for the relaytransmitter is identical to the first physical address for the relaytransmitter.
 2. The data processor according to claim 1, wherein theaddress receiver is configured to receive, from the relay transmitter,the second physical address for the relay transmitter after the dataprocessor is turned on in a state where the first physical address forthe relay transmitter is stored on the storage unit.
 3. The dataprocessor according to claim 1, further comprising an image acquiringunit configured to acquire an image, wherein the communication unitcomprises an image transmitter configured to transmit the image acquiredby the image acquiring unit.
 4. The data processor according to claim 1,wherein the communication unit comprises an image receiver configured toreceive an image from the external device via wireless communicationwith the relay transmitter, and wherein the data processor furthercomprises an image outputting unit configured to output the imagereceived by the image receiver.
 5. The data processor according to claim1, further comprising a network name creating unit configured to createa network name for a wireless network containing thereon the dataprocessor and the relay transmitter, based on the physical address forthe data processor and the first physical address for the relaytransmitter, such that the created network name is identical to anetwork name created by the relay transmitter for the wireless network,wherein the communication unit is configured to perform wirelesscommunication with the relay transmitter based on the network namecreated by the network name creating unit.
 6. The data processoraccording to claim 1, further comprising an encryption key creating unitconfigured to create an encryption key based on the physical address forthe data processor and the first physical address for the relaytransmitter, such that the created encryption key is identical to anencryption key created by the relay transmitter, wherein thecommunication unit is configured to perform encrypted wirelesscommunication with the relay transmitter using the encryption keycreated by the encryption key creating unit.
 7. The data processoraccording to claim 6, wherein the communication unit is configured toperform wireless communication with a wireless communication deviceother than the relay transmitter in any of a direct manner and anindirect manner via an access point, wherein the communication unitdetermines whether to communicate with the relay transmitter or theother wireless communication device, wherein when determining that thecommunication unit is to communicate with the relay transmitter, thecommunication unit performs encrypted communication with the relaytransmitter, wherein when determining that the communication unit is tocommunicate with the relay transmitter, the communication unit performsthe encrypted wireless communication with the relay transmitter usingthe encryption key created by the encryption key creating unit, andwherein when determining that the communication unit is to communicatewith the other wireless communication device, the communication unitperforms wireless communication with the other wireless communicationdevice without using the encryption key.
 8. A relay transmittercomprising: first communication unit configured to perform wirelesscommunication with a data processor; a second communication unitconfigured to perform data communication with an external device; astorage unit configured to store a first physical address for the dataprocessor; an address receiver configured to, in response to the relaytransmitter being turned on, wirelessly receive, from the dataprocessor, a second physical address for the data processor along withan instruction to start authentication between the data processor andthe relay transmitter; a determining unit configured to, in response tothe instruction which is received wirelessly from the data processor,make a determination as to whether the second physical address for thedata processor is identical to the first physical address for the dataprocessor which had been stored in the storage unit before the relaytransmitter is turned on; and a connecting unit configured to, when oneor more authentication requirements are satisfied, wirelessly transmit aphysical address for the relay transmitter to the data processor andestablish wireless connection between the first communication unit andthe data processor so as to achieve data communication between the dataprocessor and the external device via the relay transmitter, theauthentication requirements including the determination by thedetermining unit that the second physical address for the data processoris identical to the first physical address for the data processor. 9.The relay transmitter according to claim 8, wherein the address receiveris configured to receive, from the data processor, the second physicaladdress for the data processor after the relay transmitter is turned onin a state where the first physical address for the data processor isstored on the storage unit.
 10. The relay transmitter according to claim8, wherein the first communication unit comprises a first receiving unitconfigured to receive an image from the data processor via wirelesscommunication, and wherein the second communication unit comprises afirst transmitting unit configured to transmit the image received by thefirst receiving unit, to the external device via facsimilecommunication.
 11. The relay transmitter according to claim 8, whereinthe second communication unit comprises a second receiving unitconfigured to receive an image from the external device via facsimilecommunication, and wherein the first communication unit comprises asecond transmitting unit configured to transmit the image received bythe second receiving unit, to the data processor via wirelesscommunication.
 12. The relay transmitter according to claim 8, furthercomprising a network name creating unit configured to create a networkname for a wireless network containing thereon the data processor andthe relay transmitter, based on the physical address for the relaytransmitter and the first physical address for the data processor, suchthat the created network name is identical to a network name created bythe data processor for the wireless network, wherein the firstcommunication unit is configured to perform wireless communication withthe data processor based on the network name created by the network namecreating unit.
 13. The relay transmitter according to claim 8, furthercomprising an encryption key creating unit configured to create anencryption key based on the physical address for the relay transmitterand the first physical address for the data processor, such that thecreated encryption key is identical to an encryption key created by thedata processor, wherein the first communication unit is configured toperform encrypted wireless communication with the data processor usingthe encryption key created by the encryption key creating unit.
 14. Adata transmission system comprising: a relay transmitter configured toperform data communication with an external device; and a data processorconfigured to perform data communication with the external device viawireless communication with the relay transmitter, wherein the dataprocessor comprises: a communication unit configured to perform wirelesscommunication with the relay transmitter; a storage unit configured tostore a first physical address for the relay transmitter; anauthentication starter configured to, in response to the data processorbeing turned on, wirelessly transmit, to the relay transmitter, aninstruction to start authentication between the data processor and therelay transmitter along with a physical address for the data processor;an address receiver configured to receive a second physical address forthe relay transmitter wirelessly transmitted from the relay transmitteras a response to the instruction; a determining unit configured to makea determination as to whether the second physical address for the relaytransmitter which is received from the relay transmitter wirelessly isidentical to the first physical address for the relay transmitter whichhad been stored in the storage unit before the data processor is turnedon; and a connecting unit configured to, when one or more authenticationrequirements are satisfied, establish wireless connection between thecommunication unit and the relay transmitter so as to achieve the datacommunication between the data processor and the external device via therelay transmitter, the authentication requirements including thedetermination by the determining unit that the second physical addressfor the relay transmitter is identical to the first physical address forthe relay transmitter, and wherein the relay transmitter comprises: afirst relay-transmitter-side communication unit configured to performwireless communication with the data processor; a secondrelay-transmitter-side communication unit configured to perform datacommunication with the external device; a relay-transmitter-side storageunit configured to store a first physical address for the dataprocessor; a relay-transmitter-side address receiver configured to, inresponse to the relay transmitter being turned on, wirelessly receive,from the data processor, a second physical address for the dataprocessor along with the instruction to start authentication between thedata processor and the relay transmitter; a relay-transmitter-sidedetermining unit configured to, in response to the instruction which isreceived wirelessly from the data processor, make a determination as towhether the second physical address for the data processor is identicalto the first physical address for the data processor which had beenstored in the storage unit before the relay transmitter is turned on;and a relay-transmitter-side connecting unit configured to, when theauthentication requirements are satisfied, wirelessly transmit aphysical address for the relay transmitter to the data processor andestablish wireless connection between the first communication unit andthe data processor so as to achieve the data communication between thedata processor and the external device via the relay transmitter, theauthentication requirements including the determination by therelay-transmitter-side determining unit that the second physical addressfor the data processor is identical to the first physical address forthe data processor.
 15. The data transmission system according to claim14, wherein the address receiver is configured to receive, from therelay transmitter, the second physical address for the relay transmitterafter the data processor is turned on in a state where the firstphysical address for the relay transmitter is stored on the storageunit, and wherein the relay-transmitter-side address receiver isconfigured to receive, from the data processor, the second physicaladdress for the data processor after the relay transmitter is turned onin a state where the first physical address for the data processor isstored on the storage unit.
 16. The data transmission system accordingto claim 14, wherein the data processor further comprises an imageacquiring unit configured to acquire an image, wherein the communicationunit comprises an image transmitter configured to transmit the imageacquired by the image acquiring unit, wherein the firstrelay-transmitter-side communication unit comprises a first receivingunit configured to receive the image from the data processor viawireless communication, and wherein the second relay-transmitter-sidecommunication unit comprises a first transmitting unit configured totransmit the image received by the first receiving unit, to the externaldevice via facsimile communication.
 17. The data transmission systemaccording to claim 14, wherein the second relay-transmitter-sidecommunication unit comprises a second receiving unit configured toreceive an image from the external device via facsimile communication,wherein the first relay-transmitter-side communication unit comprises asecond transmitting unit configured to transmit the image received bythe second receiving unit, to the data processor via wirelesscommunication, wherein the communication unit comprises an imagereceiver configured to receive the image from the external device viawireless communication with the relay transmitter, and wherein the dataprocessor further comprises an image outputting unit configured tooutput the image received by the image receiver.
 18. The datatransmission system according to claim 14, wherein the data processorfurther comprises a network name creating unit configured to create anetwork name for a wireless network containing thereon the dataprocessor and the relay transmitter, based on a physical address for thedata processor and the first physical address for the relay transmitter,such that the created network name is identical to a network namecreated by the relay transmitter for the wireless network, wherein thecommunication unit is configured to perform wireless communication withthe relay transmitter based on the network name created by the networkname creating unit, wherein the relay transmitter further comprises arelay-transmitter-side network name creating unit configured to create anetwork name for the wireless network containing thereon the dataprocessor and the relay transmitter, based on the physical address forthe relay transmitter and the first physical address for the dataprocessor, such that the created network name is identical to thenetwork name created by the data processor for the wireless network, andwherein the first relay-transmitter-side communication unit isconfigured to perform wireless communication with the data processorbased on the network name created by the network name creating unit. 19.The data transmission system according to claim 14, wherein the dataprocessor further comprises an encryption key creating unit configuredto create an encryption key based on the physical address for the dataprocessor and the first physical address for the relay transmitter, suchthat the created encryption key is identical to an encryption keycreated by the relay transmitter, wherein the communication unit isconfigured to perform encrypted wireless communication with the relaytransmitter using the encryption key created by the encryption keycreating unit, wherein the relay transmitter further comprises arelay-transmitter-side encryption key creating unit configured to createan encryption key based on the physical address for the relaytransmitter and the first physical address for the data processor, suchthat the created encryption key is identical to the encryption keycreated by the data processor, and wherein the firstrelay-transmitter-side communication unit is configured to performencrypted wireless communication with the data processor using theencryption key created by the relay-transmitter-side encryption keycreating unit.
 20. The data transmission system according to claim 19,wherein the communication unit is configured to perform wirelesscommunication with a wireless communication device other than the relaytransmitter in any of a direct manner and an indirect manner via anaccess point, wherein the communication unit determines whether tocommunicate with the relay transmitter or the other wirelesscommunication device, wherein when determining that the communicationunit is to communicate with the relay transmitter, the communicationunit performs encrypted communication with the relay transmitter,wherein when determining that the communication unit is to communicatewith the relay transmitter, the communication unit performs theencrypted wireless communication with the relay transmitter using theencryption key created by the encryption key creating unit, and whereinwhen determining that the communication unit is to communicate with theother wireless communication device, the communication unit performswireless communication with the other wireless communication devicewithout using the encryption key.